To turn on "Do Not Disturb" when a Mac is sleeping, click the Apple icon → Click "System Preferences" → Click "Notifications" → Select "Do Not Disturb" → Click the check box next to "When the display is sleeping."

Steps

1

Click the Apple icon. It's the Apple logo at the top left corner of the menu bar.

2

Click System Preferences.

3

Click the "Notifications" icon. It looks like a square with a red dot in the corner.

If you don't see the Notifications icon, click on ⋮⋮⋮⋮ at the top left corner of the window, which displays as Show All in earlier versions of Mac OS X.

4

Click Do Not Disturb on the left side of the window.

5

Click the "When the display is sleeping" check box. It's on the right side of the window next to the "Turn on Do Not Disturb" section.

6

Click the red "x" button. Do Not Disturb will turn on whenever your Mac is sleeping!